Printing process



Patented Jan. 30,. 1945 PRINTING PROCESS Frank '1. Ortolano, NewOrleans, La, asslgnor to Rheem Manufacturing Company, Richmond, Calif.,a corporation of California No Drawing. Application October 18, 1941,

Serial No. 415,643

1 Claim. (Cl. fill-4B6) The invention relates to printing materials andprocesses and has for its principal object the provision of a materialand process particularly adapted for printing upon surfaces coated witha lacquer film and which will provide a speedy, rapidly drying,. durableprinted impression.

Another object of the invention is to provide a printing material andprocess of the character described in which the ink is set upon thelacquer surface by absorption of the ink solvent by the lacquer out ofthe ink, thereby enabling the latter to rapidly set up.

A further object of the invention is to provide in a printing materialand process of the character described, the combination of a fast dryingink and a slow solvent which will prevent drying of the ink on therollers, type, plates or other parts of the printing apparatus and yetfunction bythe process of absorption as above noted to rapidly set theink upon contact with the lacquer surface.

The invention possesses other objects which with the foregoing will beset forth in the. following description of the preferred forms of theinvention. It is to be understood, however, that I do not limit myselfto said description, as I may adopt variations, from said forms withinthe scope of the invention as set forth in the claim.

enable a rapid setting up of the ink upon the The material and processmay be used on hisquer films deposited by lacquers of various formulaand consistency as obtainable on the market. The manufacture of lacquersis a highly developed art in itself and since the invention may be usedwith substantially all the varying grades and types of lacquersavailableon. the a market, applicant is not concerned with anyparticular type of lacquer. Generally it may be stated that the processmay be used with any pyroxylin, nitro-cellulose and probably celluloseacetate type of lacquer, the dry film of which is readily soluble withlacquer thinner, butyl alcohol, butylcellosolve, Cellosolve and othersolvents of this type.

Similarly substantially anyof the so-called fast drying inks may be usedin the present invention. A relatively large number of such inks areavailable on the market and their specific manufacture and formula isgenerally a trade secret. Generally it may be stated that substantiallyany ink having a relatively highly volatile vehicle may be used, as forexample those formed by grinding pigments into synthetic vehicles havingno linseed oil or varnish properties. However, the type of ink hereindenoted as a fast drying ink is well known in'the art and insofar asapplicant is aware, substantially any of these fast drying inks may beused.

In accordance with the present invention 1 incorporate in the fastdrying ink a relatively slow solvent or plasticizer which is misciblewith the fast drying ink and retains the same in a wet state uponexposure to the atmosphere even for protracted periods and which hastheparticular quality of being rapidly absorbed into the lacquer film uponcontact therewith. By reason of this inclusion, the ink may be used onconventional types of printing apparatus and the ink will remain wet onthe latter for hours without appreciable change of tack or viscosity.Upon application to the lacquer film, however, the slow solvent isextracted from the ink by absorption into the lacquer film, therebypermitting the ink to set up rapidly within a period of a few secondsand varying from live to ten seconds, depending upon the amount of inkapplied and proportions used. Several slow solvents may be used in thepresent invention. Because of their common chemical properties thesesolvents are frequently classed together and include dibutyl phthalate,butyl Cellosolve, Cellosolve, dimethyl phthalate, triethylene glycol.Probably additional slow solvents may be used having the speciflcqualities of firstly being miscible with a fast drying ink to retard itssetting, and secondly being readily and substantially completelyabsorbable in a lacquer film. Of the above enumerated group I have foundthat dibutyl phthalate is preferable at least in connection with thefast drying inks tested.

The proportion of slow, solvent to fast drying ink may be variedsomewhat within the test that the amount of solvent must be sufficientlylargev 2 a,sos,1sv

completely removed from the ink by the lacquer film contaetedandconsequently the ink will remain wet and tack for an appreciable periodor time. I have found that a good average working range may be obtainedby incorporating one part 5 Y of slow solvent to approximately nineparts 01' fast drying ink. For example, the combinationof fifty c. c.dibutyl phthalate to. one pound (453 grams) oi fast drying ink, denotedin the trade as casing ink, aflorded an excellent working ma- 1o terialboth from the standpoint of delayed drying on the rolls and type orrubber printing plates of the printing apparatus and from the standpointof a rapid setting up and drying of the ink on the lacquer film. Thiscombination may be 15 adjusted for lower or higher viscosity of the inkby incorporating a minimum of approximately forty c. c. dibutylphthalate per pound 01' ink for the higher viscosity and a maximum 01approximately sixty c. c. dibutyl phthalate per pound for goathinviscositv ink.

The present material and process can be used for printing onsubstantially any lacquered surface whether the lacquer be applied topap wood, glass. metal, etc. One important use towhichthematerialandprocesshasbeenputisintheprintingotbombswheretheinkisapplied gylcol, said retardant beingincorporated in said ink in an amount sumcient to maintain said inkinawet tackystateforaprotractedpetiodin the order 01 several hours whensaid ink is spread in a thinfilm on printing type; mlying said ink v tosaid lacquer film. and setting said ink on said film within about 10seconds at atmospheric temperatures by evaporation oi said solvent andabsorption 01' said retardant into said lacquer mm.

FRANK T. ORTOLANO.

